From d69cba5c719b0c551f6380ec5da4ed8c20a3815a Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 15 Aug 2021 23:29:15 +0200 Subject: futex: Reorder sanity checks in futex_requeue() No point in allocating memory when the input parameters are bogus. Validate all parameters before proceeding. Suggested-by: Davidlohr Bueso Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210815211305.581789253@linutronix.de --- kernel/futex.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'kernel/futex.c') diff --git a/kernel/futex.c b/kernel/futex.c index 8d8bad5e07bb..a5232f62de75 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -1933,13 +1933,6 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, if (uaddr1 == uaddr2) return -EINVAL; - /* - * requeue_pi requires a pi_state, try to allocate it now - * without any locks in case it fails. - */ - if (refill_pi_state_cache()) - return -ENOMEM; - /* * futex_requeue() allows the caller to define the number * of waiters to wake up via the @nr_wake argument. With @@ -1963,6 +1956,13 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags, */ if (nr_wake != 1) return -EINVAL; + + /* + * requeue_pi requires a pi_state, try to allocate it now + * without any locks in case it fails. + */ + if (refill_pi_state_cache()) + return -ENOMEM; } retry: -- cgit